1. Field of the Invention
The disclosure relates to an image formation unit and an image formation apparatus, and is suitably applied, for example, to an electro-photographic printer (hereinafter may also be referred to as a printer).
2. Description of Related Art
A conventional printer includes: a photosensitive drum; and an exposure device such as a light emitting diode (LED) head having a lens array and light emitting elements such as LEDs. This type of printer forms an electrostatic latent image on a surface of the photosensitive drum by irradiating the surface of the photosensitive drum with light from the exposure device, and develops a toner image by adhering toner to the electrostatic latent image.
For example, this type of printer includes an exposure device attached to a printer housing, and an image formation unit that contains modularized consumables such as a photosensitive drum and various rollers, and is detachably attached to the printer housing. The printer is thus configured to improve efficiency for work such as maintenance. The image formation unit has, for example, a groove through which an end of the exposure device is inserted and positioned in proximity to the photosensitive drum. The groove has a bottom having an exposure opening that allows light from the exposure device to pass therethrough. In addition, a flexible light-shielding film is provided to close the groove.
In the state where the image formation is detached from the printer housing, the light-shielding film closes the grove section thereby preventing the photosensitive drum from being unnecessarily exposed. On the other hand, in the state where the image formation unit is attached to the printer housing, the light-shielding film is deformed by the exposure device to open the groove, thereby causing a light emitting section of the exposure device and the photosensitive drum to face each other (for example, see Japanese Patent Application Laid-Open No. 2012-27253 (FIGS. 1 and 2)).